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Abstract:

A projector device includes: a light modulating element which modulates
light from a light source section according to an image signal; a
projecting section which projects a modulation light modulated by a
displayable region in a surface of an effective region of the light
modulating element onto a projection surface; a trapezoidal distortion
correcting section which corrects trapezoidal distortion of a projection
image projected onto the projection surface by projecting a light
modulation image by means of the displayable region by an
after-correction image region which is a part of the effective region of
the light modulating element; and a position adjusting section which
adjusts the position of the projection image projected onto the
projection surface by moving the after-correction image region in the
surface of the effective region while maintaining the size and shape of
the after-correction image region.

Claims:

1. A projector device comprising: a light modulating element which
modulates light from a light source section according to an image signal;
a projecting section which projects a modulation light modulated by a
displayable region in a surface of an effective region of the light
modulating element onto a projection surface; a trapezoidal distortion
correcting section which corrects trapezoidal distortion of a projection
image projected onto the projection surface by projecting a light
modulation image by means of the displayable region by an
after-correction image region which is apart of the effective region of
the light modulating element; and a position adjusting section which
adjusts the position of the projection image projected onto the
projection surface by moving the after-correction image region in the
surface of the effective region while maintaining the size and shape of
the after-correction image region.

2. The projector device according to claim 1, wherein the position
adjusting section moves the after-correction image region with at least
two corners thereof being in internal contact with the effective region.

3. The projector device according to claim 1, further comprising a
manipulation section which adjusts the movement amount of the
after-correction image region in the effective region after the
projection image is projected, wherein the position adjusting section
adjusts the position of the projection image according to manipulation of
the manipulation section.

4. The projector device according to claim 3, wherein the manipulation
section includes a longitudinal manipulation section which is manipulated
when a longitudinal trapezoidal distortion correction is performed by the
trapezoidal distortion correcting section and a transverse manipulation
section which is manipulated when a transverse trapezoidal distortion
correction is performed by the trapezoidal distortion correcting section.

5. The projector device according to claim 4, wherein the manipulation
section includes a knob movable manipulator which adjusts the movement
amount of the after-correction image region using a displacement amount
of a knob.

6. The projector device according to claim 3, wherein the manipulation
section includes a lever type manipulator which adjusts the movement
direction and the movement amount of the after-correction image region
using the inclination direction and inclination amount of a lever.

7. A projection method of a projector device which includes a light
modulating element which modulates light from alight source section
according to an image signal and projects a modulation light modulated by
a displayable region in a surface of an effective region of the light
modulating element onto a projection surface, the method comprising:
correcting trapezoidal distortion of a projection image projected onto
the projection surface by projecting a light modulation image by means of
the displayable region by an after-correction image region which is apart
of the effective region of the light modulating element; and adjusting
the position of the projection image projected onto the projection
surface by moving the after-correction image region in the surface of the
effective region while maintaining the size and shape of the
after-correction image region.

Description:

BACKGROUND

[0001] 1. Technical Field

[0002] The present invention relates to a projector device which has a
trapezoidal distortion correcting function which corrects trapezoidal
distortion of a projection image projected on a projection surface, and a
projection method thereof.

[0003] 2. Related Art

[0004] In the related art, there has been known a projector device which
corrects trapezoidal distortion of a projection image projected on a
projection surface by correcting an image in a displayable region of a
light modulating element which modulates light from a light source (refer
to JP-A-2006-005534).

[0005] The projector device reduces and corrects the image in the
displayable region of the light modulating element according to an
after-correction image region of the light modulating element
corresponding to an outline of the projection surface in a state where an
entire projection region projected from an entire surface of the light
modulating element is enlarged to cover the projection surface (screen),
and corrects trapezoidal distortion of the projection image. At this
time, respective pixels of the light modulating element in which the
image in the displayable region is reduced for correction and the image
is not projected for display are controlled to be all displayed as a
black image so as not to transmit light from the light source.

[0006] In this regard, as a technique to adjust the position of a
projection image projected on a projection surface, a lens shift function
of a zoom lens or a technique of changing an installation angle of a
projector device itself has been studied. However, in such a technique, a
projection light axis with respect to the projection surface is changed,
thereby causing remarkable trapezoidal distortion in the projection
image. Thus, if the position of the projection image is adjusted after
the trapezoidal distortion is corrected, such a trapezoidal distortion
correcting process should be repeated, thereby making the process
complicated. Further, such a mechanical adjusting technique does not
provide a minute position adjustment, thereby making it difficult to
perform adjustment according to a user's wish.

SUMMARY

[0007] An advantage of some aspects of the invention is that it provides a
projector device and a projection method thereof which can easily and
appropriately perform a position adjustment of a projection image after
trapezoidal distortion correction.

[0008] According to an aspect of the invention, there is provided a
projector device including: a light modulating element which modulates
light from a light source section according to an image signal; a
projecting section which projects a modulation light modulated by a
displayable region in a surface of an effective region of the light
modulating element onto a projection surface; a trapezoidal distortion
correcting section which corrects trapezoidal distortion of a projection
image projected onto the projection surface by projecting a light
modulation image by means of the displayable region by an
after-correction image region which is a part of the effective region of
the light modulating element; and a position adjusting section which
adjusts the position of the projection image projected onto the
projection surface by moving the after-correction image region in the
surface of the effective region while maintaining the size and shape of
the after-correction image region.

[0009] According to another aspect of the invention, there is provided a
projection method of a projector device which includes a light modulating
element which modulates light from a light source section according to an
image signal and projects a modulation light modulated by a displayable
region in a surface of an effective region of the light modulating
element onto a projection surface, the method including: correcting
trapezoidal distortion of a projection image projected onto the
projection surface by projecting a light modulation image by means of the
displayable region by an after-correction image region which is a part of
the effective region of the light modulating element; and adjusting the
position of the projection image projected onto the projection surface by
moving the after-correction image region in the surface of the effective
region while maintaining the size and shape of the after-correction image
region.

[0010] According to these configurations, since the after-correction image
region is moved by the position adjusting section, it is possible to
adjust the position of the projection image without changing a projection
light axis with respect to the projection surface. Thus, since a large
trapezoidal distortion is not generated in the projection image after the
position adjustment, it is possible to simplify the image processing
without repeatedly correcting the trapezoidal distortion after the
position adjustment. Further, since the after-correction image region on
the light modulating element moves in the effective region while
maintaining the size and shape thereof, it is possible to easily perform
the image processing according to the position adjustment, to perform the
movement in units of pixels of the light modulating element, and to
accurately perform a minute position adjustment of the projection image.
Further, it is possible to effectively utilize pixels which are not used
in a region other than the after-correction image region in the effective
region of the light modulating element.

[0011] In this case, the position adjusting section may move the
after-correction image region with at least two corners thereof being in
internal contact with the effective region.

[0012] According to these configurations, the after-correction image
region can occupy the maximum area in the effective region, and thus, it
is possible to effectively use the light modulating element to the
maximum.

[0013] Further, the projector device may further include a manipulation
section which adjusts the movement amount of the after-correction image
region in the effective region after the projection image is projected,
and the position adjusting section may adjust the position of the
projection image according to manipulation of the manipulation section.

[0014] According to this configuration, it is possible to adjust the
position of the projection image by a user desired amount according to a
user's manipulation.

[0015] In this case, the manipulation section may include a longitudinal
manipulation section which is manipulated when a longitudinal trapezoidal
distortion correction is performed by the trapezoidal distortion
correcting section and a transverse manipulation section which is
manipulated when a transverse trapezoidal distortion correction is
performed by the trapezoidal distortion correcting section.

[0016] According to this configuration, it is possible to adjust the
position of the projection image with intuitive manipulation through two
manipulation sections of the longitudinal manipulation section and the
transverse manipulation section.

[0017] In this case, the manipulation section may include a knob movable
manipulator which adjusts the movement amount of the after-correction
image region using a displacement amount of a knob.

[0018] According to this configuration, since the adjustment can be
performed using the displacement amount of the knob, it is possible to
continuously adjust the position of the projection image. Further, the
knob movable manipulator may employ any one of a linear knob type in
which a knob moves (slides) linearly and a rotary knob type in which a
knob rotates.

[0019] Further, the manipulation section may include a lever type
manipulator which adjusts the movement direction and the movement amount
of the after-correction image region using the inclination direction and
inclination amount of a lever.

[0020] According to this configuration, since the adjustment can be
performed using the inclination direction and inclination amount of the
lever, it is possible to intuitively and continuously adjust the position
of the projection image. Further, the lever type manipulator may employ a
joy stick, a cross lever, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention will be described with reference to the accompanying
drawings, wherein like numbers reference like elements.

[0022]FIG. 1 is a block diagram illustrating a control configuration of a
projector device.

[0023]FIG. 2A is a diagram illustrating an image and a projection image
in a displayable region of a light modulating element before a
trapezoidal distortion correction process, and FIG. 2B is a diagram
illustrating an image and a projection image in a displayable region of a
light modulating element after a trapezoidal distortion correction
process.

[0024]FIG. 3A is a front view of a manipulation panel and FIG. 3B is an
enlarged perspective view illustrating a position adjusting knob.

[0025]FIG. 4 is a perspective view schematically illustrating a remote
controller of a projector device.

[0026]FIG. 5 is a flowchart illustrating a projection process of a
projector device.

[0027]FIG. 6A is a diagram illustrating an image and a projection image
in a displayable region of a light modulating element before a position
adjusting process in the longitudinal direction, and FIGS. 6B and 6C are
diagrams illustrating an image and a projection image in a displayable
region of a light modulating element after a position adjusting process.

[0028]FIG. 7A is a diagram illustrating an image and a projection image
in a displayable region of a light modulating element before a position
adjusting process in the transverse direction, and FIGS. 7B and 7C are
diagrams illustrating an image and a projection image in a displayable
region of a light modulating element after a position adjusting process.

[0029]FIG. 8A is a diagram illustrating an image and a projection image
in a displayable region of a light modulating element before a position
adjusting process in the longitudinal and transverse directions, and FIG.
8B is a diagram illustrating an image and a projection image in a
displayable region of a light modulating element after a position
adjusting process.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0030] Hereinafter, a projector device and a projection method thereof
according to an embodiment of the invention will be described with
reference to the accompanying drawings. FIG. 1 is a block diagram
illustrating a configuration of a projector device 1. As shown in the
figure, the projector device 1 includes a signal input section 11, an
image processing section 12, a projection control section 13, a
projection optical system 14, an image capturing section 15, a
manipulation section 16, and a central control section 17 which controls
overall the above sections.

[0031] The signal input section 11 receives an image signal from an
external device 10 such as a personal computer or a video recorder. That
is, the signal input section 11 is realized by an interface which
receives an RGB signal output from the personal computer or a composite
signal output from the video recorder. In this embodiment, the image
signal is received from the external device 10 through the signal input
section 11, but a configuration in which it is detected whether a
recording medium (USB memory or SD memory card) is inserted or the image
signal is read out from the recording medium may be used.

[0032] The image processing section 12 performs a predetermined process on
the basis of an image processing program stored in advance, with respect
to the image signal input through the signal input section 11. A light
modulation image data is generated from the image signal through the
predetermined process, and a light modulation image 100 (image in a
displayable region) is projected from a liquid crystal light valve 34
(light modulating element) which will be described later, on the basis of
the light modulation image data. A region on the light modulating element
corresponding to the light modulation image 100 is assumed as a
displayable region 54.

[0033] The image processing section 12 includes a trapezoidal distortion
correcting section 21 which performs a trapezoidal distortion correcting
process, and a position adjusting section 22 which performs an image
position adjusting process. Further, the image processing section 12
includes respective processing sections which perform processes (for
example, a screen size adjusting process, an image quality adjusting
process, a gamma correcting process, an image composing process, and the
like) other than the above processes (not shown).

[0034] In a case where there exists trapezoidal distortion to a projection
image 200 projected to a projection surface 30, the trapezoidal
distortion correcting section 21 corrects the light modulation image data
to thereby perform the trapezoidal distortion correcting process.
Specifically, the image captured data transmitted by the image capturing
section 15 which will be described later is processed and the amount of
position offsets of four corners of the projection image 200 with respect
to a projection frame (screen frame) of the projection surface 30 is
calculated, and thus, it is determined whether the trapezoidal distortion
is generated or not. Then, in order to change the trapezoidal shape of
the projection image 200 into a rectangular shape, the light modulation
image 100 (displayable region 54) is projected from an after-correction
image region 51 which is a part of an effective region 50 of the liquid
crystal light valve 34, to thereby correct the trapezoidal distortion of
the projection image 200 (refer to FIG. 2B). The trapezoidal distortion
correcting process may not be automatically performed, and a user may
manipulate the manipulation section 16 to perform the trapezoidal
distortion correction.

[0035] After the trapezoidal distortion correcting process is completed by
the trapezoidal distortion correcting section 21, the position adjusting
section 22 moves the after-correction image region 51 in the effective
region 50 of the liquid crystal light valve 34 to thereby perform
adjustment of the projection position of the projection image 200. In
this case, the position adjusting section 22 moves the after-correction
image region 51 while maintaining the size and shape thereof (refer to
FIGS. 6A to 8B).

[0036] The projection control section 13 calculates a grayscale value
corresponding to each pixel of the liquid crystal light valve 34 (light
modulating element) on the basis of the light modulation image data
generated by the image processing section 12, and performs a projection
control on the basis of grayscale values of all pixels.

[0037] The projection optical system 14 projects the projection image 200
on the projection surface 30, and includes a lamp driving section 31, a
light valve driving section 32, a light source section 33, the liquid
crystal light valves 34 (34R, 34G, and 34B) corresponding to the three
primary colors, and a projection lens 35.

[0038] Each liquid crystal light valve 34 is formed, for example, by a
liquid crystal display panel in which liquid crystals are sealed between
a pair of transparent substrates. On an inner surface of each transparent
substrate, a transparent electrode capable of applying a driving voltage
to the liquid crystal for every minute region is formed in a matrix
format as a pixel. The light valve driving section 32 applies the driving
voltage according to the light modulation image data (grayscale values of
all pixels) to each pixel of the liquid crystal light valve 34, to
thereby set the light transmittance of each pixel to display the light
modulation image 100.

[0039] The light source section 33 can employ a halogen lamp, a metal
halide lamp, or a high-pressure mercury lamp. Further, a solid light
source such as laser or LED may be used instead. The lamp driving section
31 turns on the light source section 33 on the basis of a turn-on command
from the projection control section 13.

[0040] An illumination light emitted from the light source section 33 is
separated into color lights of R, G, and B by a light separation optical
system (not shown) and is modulated by passing through the liquid crystal
light valve 34 for each color. The modulated light (light modulation
image 100) is composed for every pixel by a light composing optical
system (not shown, a dichroic prism or the like) to be color-imaged, and
the color image light which is color-imaged is projected through the
projection lens 35, and the colored projection image 200 is displayed on
the projection surface 30.

[0041] Further, instead of the above-described liquid crystal display
method, other methods may be applied to the projection optical system 14.
Specifically, there is a projection method using a DMD (Digital Micro
mirror Device), that is, a so-called DLP (Digital Light Processing)
method. Here, the DLP method refers to a method of collecting the light
of a white glow lamp using a lens to direct the light to the DMD, and
enlarging the light when each mirror of the DMD is inclined in a turned
on state using a different lens to project the light to a screen, to
which the invention can be applied.

[0042] The image capturing section 15 is configured by a CCD camera or the
like, and captures the projection image 200 which is projected on the
projection surface 30. The image captured data is transmitted to the
image processing section 12, and the trapezoidal distortion correcting
process is performed on the basis of the image captured data by the
trapezoidal distortion correcting section 21.

[0043] The manipulation section 16 is a section in which a variety of
settings and manipulations are performed by a user, and includes a
manipulation panel 41 installed on a main body of the projector device 1,
a remote controller light receiver 42, and a remote controller 43. A
position adjusting knob 63 for adjusting the position of the projection
image 200 is installed on the manipulation panel 41 (refer to FIGS. 3A
and 3B). On the other hand, a position adjusting stick 72 is installed on
the remote controller 43 (refer to FIG. 4).

[0044] The central control section 17 is configured by a CPU (Central
Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory),
and the like (none of them not shown), and controls the entire projector.
A specific process (projecting process) of the central control section 17
will be described later.

[0045] Here, the trapezoidal distortion correcting process of the image
will be described with reference to FIGS. 2A and 2B. FIGS. 2A and 2B
illustrate the light modulation image 100 (displayable region 54)
displayed in the effective region 50 of the liquid crystal light valve 34
and the projection image 200 in which the light modulation image 100 is
projected to the projection surface 30. As shown in FIG. 2A, the
trapezoidal distortion is generated in the projection image 200 to which
the light modulation image 100 is projected (in the figure, longitudinal
trapezoidal distortion). As shown in FIG. 2B, the trapezoidal distortion
correcting section 21 corrects the light modulation image data and
deforms the light modulation image 100 so that the light modulation image
100 has a shape in which the trapezoidal distortion of the projection
image 200 is compensated. Thus, the projection image 200 is changed from
the trapezoidal shape to the rectangular shape, and thus, the trapezoidal
distortion is removed. At this time, the trapezoidal distortion
correcting section 21 corrects the light modulation image data so that
the area of the light modulation image 100 (displayable region 54) after
deformation in the effective region 50 becomes the maximum. The region
where the deformed light modulation image 100 (displayable region 54) is
displayed is the after-correction image region 51.

[0046] However, in the effective region 50 of the liquid crystal light
valve 34 after the trapezoidal distortion correcting process, an image
mask region 52 which is a different region from the displayable region 54
displays a black image by lowering the light transmittance by a
combination of a polarization plate in order not to transmit the
projection light. In addition, in the projection surface 30, a projection
mask region 53 to which the black image of the image mask region 52 is
projected is present. The image mask region 52 is a pixel region
generated by reducing at least a part of the light modulation image 100
to compensate for the trapezoidal distortion of the projection image 200,
and in actuality, is an image displayable region. Accordingly, the
projection mask region 53 is an image projectable region. The position
adjusting section 22 of this embodiment performs the position adjustment
of the projection image 200 by using the image mask region 52 and moving
the after-correction image region 51.

[0047] Next, a position adjusting manipulation function of the projection
image 200 in the manipulation section 16 of the projector device 1 will
be described with reference to FIGS. 3A, 3B, and 4. FIG. 3A illustrates
the manipulation panel 41 installed on the main body of the projector
device 1. The manipulation panel 41 includes a power button 61, a button
group 62 through which a variety of manipulations is performed, and a
position adjusting knob 63 for adjusting the projection position of the
projection image 200.

[0048] The position adjusting knob 63 includes a longitudinal manipulation
knob 63a which manipulates the projection image 200 in the longitudinal
direction (up and down directions), and a transverse manipulation knob
63b which manipulates the projection image 200 in the transverse
direction (left and right directions). The longitudinal manipulation knob
63a and the transverse manipulation knob 63b area so-called knob movable
manipulator, which includes a knob section 64 which is gripped by a user
for manipulation, a slide section 65 which is connected to the knob
section 64, and a slide groove 66 in which the slide section 65 slides,
as shown in FIG. 3B. The user adjusts the projection position of the
projection image 200 by sliding the knob section 64 in a range of the
slide groove 66. On the other hand, the position adjusting section 22 of
the image processing section 12 adjusts the movement amount of the light
modulation image 100 (after-correction image region 51) according to the
displacement amount of the slide section 65. Instead of such a linear
knob which moves (slides) the knob in a linear direction, the position
adjusting knob 63 may be configured by a rotational knob which rotates a
knob.

[0049]FIG. 4 illustrates the remote controller 43 for remotely
controlling the projector device 1. The remote controller 43 includes a
remote controller button group 71 through which the same manipulations as
the manipulation panel 41 are performed, and a position adjusting stick
72 (lever type manipulator) for adjusting the projection position of the
projection image 200. The position adjusting stick 72 is a so-called joy
stick, and the user performs the position adjustment of the projection
image 200 by inclining a stick section 73 vertically and horizontally. On
the other hand, the position adjusting section 22 of the image processing
section 12 adjusts the movement direction and the movement amount of the
light modulation image 100 (after-correction image region 51) on the
basis of the inclination direction and the inclination amount of the
stick section 73. The position adjusting stick 72 may be configured as a
cross lever in which a stick is manipulated vertically and horizontally,
or a cross button capable of changing the adjustment amount by the
pressing time corresponding to up, down, left, and right.

[0050] In this way, as the position adjusting manipulation function of the
projection image is provided in the manipulation section 16, it is
possible to adjust the position of the projection image 200 by a user
desired amount, according to a manipulation of the user. Further, it is
possible to intuitively and continuously adjust the projection position
of the projection image 200 by the position adjusting knob 63 and the
position adjusting stick 72. The position adjusting stick 72 may be
installed on the manipulation panel 41, or the position adjusting knob 63
may be installed on the remote controller 43.

[0051] Further, the manipulation section 16 may be configured by a touch
pad or a touch panel of an electrostatic capacitance type which is
mounted on a typical notebook personal computer. According to such a
configuration, space saving of the manipulation section 16 is realized
and the user can more intuitively perform the position adjustment of the
projection image 200. In particular, if the touch panel capable of
detecting a plurality of points is used, it is possible to perform
zoom-out and zoom-in using a pinch operation by two-point simultaneous
detection on the panel. Thus, longitudinal movement, transverse movement,
and enlargement and reduction in the projection image can be manipulated
at one time, to thereby enhance manipulation performance.

[0052] Next, a projection process (projection method) of the projector
device 1 will be described with reference to FIG. 5. If an image signal
is input through the signal input section 11 (S01), the projector device
1 (central control section 17) performs a predetermined process for the
image signal by the image processing section 12 to thereby generate the
light modulation image data (502). Then, the light modulation image 100
based on the light modulation image data is displayed on the liquid
crystal light valve 34 by the projection control section 13 (S03). The
light modulation image 100 is projected onto the projection surface 30 by
the projection optical system 14 (SO4). Subsequently, the projection
image 200 projected to the projection surface 30 is captured by the image
capturing section 15 (505), and the captured image data is transmitted to
the image processing section 12, and then it is determined whether the
trapezoidal distortion is generated in the projection image 200 (S06).

[0053] In a case where the trapezoidal distortion is not generated (S06;
NO), the trapezoidal distortion correcting process and the position
adjustment processing image process are not performed, and the procedure
is terminated. On the other hand, in a case where the trapezoidal
distortion is generated in the projection image 200, the trapezoidal
distortion correcting process is performed by the trapezoidal distortion
correcting section 21 (S07). Then, in a case where the position adjusting
manipulation is performed by the manipulation section 16 (S08; YES), the
position adjusting process is performed by the position adjusting section
22 (S09), and then the projection process is terminated. Further, in a
case where the position adjusting manipulation is not performed (S08;
NO), the projection process is terminated as it is.

[0054] Subsequently, the position adjusting process of the image will be
described with reference to FIGS. 6A, 6B, and 6C, to FIGS. 8A and 8B.
FIGS. 6A to 6C illustrate the projection image 200 and the light
modulation image 100 after the longitudinal trapezoidal distortion of the
projection image 200 is corrected. As shown in FIG. 6A, the light
modulation image 100 (after-correction image region 51) displayed on the
effective region 50 of the liquid crystal light valve 34 has the image
mask region 52 on the upper side thereof, and thus is movable upward. The
position adjusting section 22 corrects the light modulation image data
according to the manipulation of the manipulation section 16 by the user
and moves the light modulation image 100 (after-correction image region
51) in the effective region 50 upward and downward. Through the movement
of the light modulation image 100, the projection image 200 moves upward
and downward as shown in the figure. At this time, the position adjusting
section 22 moves the light modulation image 100 with two corners (point
A1 and point B1) thereof being in internal contact with the effective
region 50 and the size and shape thereof being maintained. Actually, as
shown in FIGS. 6A to 6C, if the light modulation image 100 moves upward
with two corners thereof being in internal contact with the effective
region 50, the projection image 200 is slightly enlarged (refer to FIGS.
6B and 6C).

[0055] FIGS. 7A to 7C illustrate the projection image 200 and the light
modulation image 100 after the transverse trapezoidal distortion of the
projection image 200 is corrected. As shown in FIG. 7A, the light
modulation image 100 (after-correction image region 51) has the image
mask region 52 on the right side, and thus is movable to the right side.
The position adjusting section 22 corrects the light modulation image
data according to the manipulation of the manipulation section 16 by the
user, and moves the light modulation image 100 (after-correction image
region 51) in the effective region 50 in the left and right directions.
Through the movement of the light modulation image 100, the projection
image 200 moves in the left and right directions as shown in the figure.
At this time, the position adjusting section 22 moves the light
modulation image 100 with two corners (point A2 and point B2) thereof
being in internal contact with the effective region 50 and the size and
shape thereof being maintained. Actually, as shown in FIGS. 7A to 7C, if
the light modulation image 100 moves in the right direction with two
corners thereof being in internal contact with the effective region 50,
the projection image 200 is slightly enlarged (refer to FIGS. 7B and 7C).

[0056] FIGS. 8A and 8B illustrate the projection image 200 and the light
modulation image 100 after the longitudinal and transverse trapezoidal
distortions are corrected. The light modulation image 100 is movable in
the right direction. The position adjusting section 22 corrects the light
modulation image data according to the manipulation of the manipulation
section 16 by the user, and moves the light modulation image 100
(after-correction image region 51) in the effective region 50 in the left
and right directions. Through the movement of the light modulation image
100, the projection image 200 moves in the left and right directions as
shown in the figure. At this time, the position adjusting section 22
moves the light modulation image 100 with two corners (point A3 and point
B3) thereof being in internal contact with the effective region 50 and
the size and shape thereof being maintained. Actually, as shown in FIGS.
8A to 8B, if the light modulation image 100 moves in the right direction
with two corners thereof being in internal contact with the effective
region 50, the projection image 200 is slightly enlarged (refer to FIGS.
8A and 8B).

[0057] As described above, according to the projector device 1 in this
embodiment, since the position adjustment of the projection image 200 is
performed by correcting the light modulation image data, it is possible
to easily perform the position adjustment of the image without repeatedly
generating a large trapezoidal distortion in the projection image 200
after the position adjustment. Further, it is possible to perform the
movement in units of pixels and to accurately perform a minute position
adjustment. Furthermore, since the light modulation image 100
(after-correction image region 51) moves by using the image mask region
52 in the effective region 50, it is possible to effectively utilize the
pixels of the liquid crystal light valve 34. Further, since the light
modulation image 100 (after-correction image region 51) moves inside the
effective region 50 with two corners thereof being in internal contact
with the effective region 50, it is possible to constantly maximize the
area of the light modulation image 100 in the effective region 50 of the
liquid crystal light valve 34, and to prevent deterioration of the
projection image 200 by preventing reduction in the number of pixels
corresponding to the light modulation image 100. Further, since the light
modulation image 100 moves inside the effective region 50 with the size
and shape thereof being maintained, the image processing according to the
position adjustment becomes easy.

[0058] In the above-described embodiment, the size of the projection image
200 is slightly enlarged through the movement of the after-correction
image region 51 by the position adjusting section 22, but the reduction
processing of the light modulation image 100 may be performed so that the
size of the projection image 200 becomes identical before adjustment and
after adjustment. That is, in order to perform the position adjustment
while maintaining the screen size in the projection surface 30 as the
same area, the position adjusting section 22 may perform adjustment so
that the light modulation image 100 moves according to the manipulation
of the manipulation section 16, and then further corrects the light
modulation data to reduce the light modulation image 100
(after-correction image region 51) inwardly while maintaining the image
position, so that the projection screen 200 before the movement and the
projection screen 200 after the movement have the same area. Further,
after the movement of the after-correction image region 51 or at the time
of reduction processing of the light modulation image 100, the
trapezoidal distortion correction process through the trapezoidal
distortion correcting section 21 may be performed again.

[0059] It is possible to provide the respective components of the
projector device in the above-described embodiment as a program. Further,
the program may be stored in a variety of recording mediums (CD-ROM,
flash memory, or the like) and provided. That is, a program for allowing
a computer to function as the respective components of the projector
device, and a recording medium which records this program are included in
the scope of the invention. Further, modifications may be made in the
range without departing from the spirit of the invention.

Patent applications by Yoshiteru Uchiyama, Suwa-Shi JP

Patent applications by SEIKO EPSON CORPORATION

Patent applications in class For projection axis inclined to screen

Patent applications in all subclasses For projection axis inclined to screen